Marble sliced loaf cake with vanilla-flavored icing

Sugar, enriched wheat flour (wheat flour, niacin, reduced iron, thiamine mononitrate, riboflavin, folic acid), eggs, soybean oil, water, semisweet chocolate chips (sugar, chocolate liquor, cocoa butter, dextrose, soy lecithin, salt, natural flavor), bleached enriched wheat flour (wheat flour, niacin, reduced iron, thiamine mononitrate, riboflavin, folic acid), butter (cream [milk], natural flavor), buttermilk (cultured low fat milk, nonfat milk, food starch-modified, sodium citrate, locust bean gum, carrageenan, mono - and diglycerides, salt, vitamin a palmitate, vitamin d3), food starch-modified, dry whole milk, cocoa processed with alkali, wheat starch, leavening (sodium bicarbonate, sodium acid pyrophosphate, monocalcium phosphate), natural flavor, salt, xanthan gum, soy lecithin, citric acid, cellulose gum. icing: icing sugar (sugar, cornstarch), buttermilk (cultured low fat milk, nonfat milk, food starch-modified, sodium citrate, locust bean gum, carrageenan, mono - and diglycerides, salt, vitamin a palmitate, vitamin d3), butter (cream [milk], natural flavor), palm oil shortening, corn syrup, guar gum, natural flavor, mono - and diglycerides.